Origin of Covid ? Following the Clues
Did people or nature open Pandora?s box at Wuhan?
Nicholas Wade
2 days ago?
43 min read
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Before 2020, the rules followed by virologists in China and elsewhere required that experiments with the SARS1 and MERS viruses be conducted in BSL3 conditions. But all other bat coronaviruses could be studied in BSL2, the next level down. BSL2 requires taking fairly minimal safety precautions, such as wearing lab coats and gloves, not sucking up liquids in a pipette, and putting up biohazard warning signs. Yet a gain-of-function experiment conducted in BSL2 might produce an agent more infectious than either SARS1 or MERS. And if it did, then lab workers would stand a high chance of infection, especially if unvaccinated.
Much of Dr. Shi?s work on gain-of-function in coronaviruses was performed at the BSL2 safety level, as is stated in her publications and other documents. She has said in an
interview with Science magazine that ?The coronavirus research in our laboratory is conducted in BSL-2 or BSL-3 laboratories.?
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Concern about safety conditions at the Wuhan lab was not, it seems, misplaced. According to a
fact sheet issued by the State Department on January 21,2021, ? The U.S. government has reason to believe that several researchers inside the WIV became sick in autumn 2019, before the first identified case of the outbreak, with symptoms consistent with both COVID-19 and common seasonal illnesses.?
David Asher, a fellow of the Hudson Institute and former consultant to the State Department, provided more detail about the incident at a
seminar. Knowledge of the incident came from a mix of public information and ?some high end information collected by our intelligence community,? he said. Three people working at a BSL3 lab at the institute fell sick within a week of each other with severe symptoms that required hospitalization. This was ?the first known cluster that we?re aware of, of victims of what we believe to be COVID-19.? Influenza could not completely be ruled out but seemed unlikely in the circumstances, he said.
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In the case of SARS1, researchers have documented the successive changes in its spike protein as the virus evolved step by step into a dangerous pathogen. After it had gotten from bats into civets, there were six further changes in its spike protein before it became a mild pathogen in people. After a further 14 changes, the virus was much better adapted to humans, and with a further 4 the
epidemic took off.
But when you look for the fingerprints of a similar transition in SARS2, a strange surprise awaits. The virus has changed hardly at all, at least until recently. From its very first appearance, it was well adapted to human cells. Researchers led by Alina Chan of the Broad Institute compared SARS2 with late stage SARS1, which by then was well adapted to human cells, and found that the two viruses were similarly well adapted. ?By the time SARS-CoV-2 was first detected in late 2019, it was already pre-adapted to human transmission to an extent similar to late epidemic SARS-CoV,? they
wrote.
Even those who think lab origin unlikely agree that SARS2 genomes are remarkably uniform. Dr. Baric writes that ?early strains identified in Wuhan, China, showed limited genetic diversity, which suggests that the virus may have been introduced from a single source.?
A single source would of course be compatible with lab escape, less so with the massive variation and selection which is evolution?s hallmark way of doing business.
The uniform structure of SARS2 genomes gives no hint of any passage through an intermediate animal host, and no such host has been identified in nature.
Proponents of natural emergence suggest that SARS2 incubated in a yet-to-be found human population before gaining its special properties. Or that it jumped to a host animal outside China.
All these conjectures are possible, but strained. Proponents of lab leak have a simpler explanation. SARS2 was adapted to human cells from the start because it was grown in humanized mice or in lab cultures of human cells, just as described in Dr. Daszak?s grant proposal. Its genome shows little diversity because the hallmark of lab cultures is uniformity.
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Full text:
https://nicholaswade.medium.com/origin-of-covid-following-the-clues-6f03564c038
